Methods and systems for multi-directional time preservation distribution in multi-communication core devices

ABSTRACT

A system and method for the distribution of time signals is available for devices with multiple communication cores. An embodiment may or may not use a centralized manager for the management of time preservation. When a communication core in a multiple communication core device requires timing information, it may request the time information from another communication core or from the centralized manager. The centralized manager, if present, can obtain time information from an external source or from one of the communication cores. The result can be reduced power consumption at a lower cost.

TECHNICAL FIELD

Embodiments pertain to wireless communications. Some embodiments pertainto wireless communication devices that are capable of communicating onmultiple communication cores.

BACKGROUND ART

Mobile communication devices such as phones, tablets, e-book readers,laptop computers, and the like, have become increasingly common. Manysuch devices have multiple cores, such as computing cores andcommunication cores. That is, they are able to transmit and receive datavia a variety of different methods, such as cellular, WiFi, Bluetooth,near-field communications (NFC), high-definition radio (HDR), globalnavigation satellite systems (GNSS), and the like. Each of thesecommunication cores needs to maintain time preservation in order tooperate properly, without using an excessive amount of power.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram presenting an overview of an embodiment;

FIG. 2 is a block diagram presenting an overview of another embodiment.

FIG. 3 is a flow chart illustrating the operation of an exemplaryembodiment.

FIG. 4 is a flow chart illustrating the operation of another exemplaryembodiment.

FIG. 5 is a block diagram illustrating a system containing anembodiment.

DESCRIPTION OF THE EMBODIMENTS

The following description and the drawings sufficiently illustratespecific embodiments to enable those skilled in the art to practicethem. Other embodiments may incorporate structural, logical, electrical,process, and other changes. Examples merely typify possible variations.Individual components and functions are optional unless explicitlyrequired, and the sequence of operations may vary. Portions and featuresof some embodiments may be included in, or substituted for, those ofother embodiments. Embodiments set forth in the claims encompass allavailable equivalents of those claims.

In the following detailed description, numerous specific details are setforth in order to provide a thorough understanding of the invention.However, it will be understood by those skilled in the art that thepresent invention may be practiced without these specific details. Inother instances, well-known methods, procedures, components, andcircuits have not been described in detail so as not to obscureembodiments of the present invention.

Although embodiments of the invention are not limited in this regard,the terms “plurality” and “a plurality” as used herein may include, forexample, “multiple” or “two or more.” The terms “plurality” or “aplurality” may be used throughout the specification to describe two ormore components, devices, elements, units, parameters, and the like. Forexample, “a plurality of stations” may include two or more stations.

The 3rd Generation Partnership Project (3GPP) is a collaborationagreement established in December 1998 to bring together a number oftelecommunications standards bodies, known as “Organizational Partners,”that currently include the Association of Radio Industries and Business(ARIB), the China Communications Standards Association (CCSA), theEuropean Telecommunications Standards Institute (ETSI), the Alliance forTelecommunications Industry Solutions (ATIS), the TelecommunicationsTechnology Association (TTA), and the Telecommunication TechnologyCommittee (TTC). The establishment of 3GPP was formalized in December1998 by the signing of the “The 3rd Generation Partnership ProjectAgreement.”

3GPP provides globally applicable standards as Technical Specificationsand Technical Reports for a 3rd Generation Mobile System based onevolved GSM core networks and radio access technologies that theysupport (e.g., Universal Terrestrial Radio Access (UTRA) for bothFrequency Division Duplex (FDD) and Time Division Duplex (TDD) modes).3GPP also provides standards for maintenance and development of theGlobal System for Mobile communication (GSM) as Technical Specificationsand Technical Reports including evolved radio access technologies (e.g.,General Packet Radio Service (GPRS) and Enhanced Data rates for GSMEvolution (EDGE)). Technical Specifications for current standardsrelated to mobile telephony are generally available to the public fromthe 3GPP organization.

3GPP is currently studying the evolution of the 3G Mobile System andconsiders contributions (views and proposals) directed toward theevolution of the UTRA Network (UTRAN). A set of high-level requirementswas identified by 3GPP workshops including: reduced cost per bit;increased service provisioning (i.e., more services at lower cost withbetter quality); flexibility of use of existing and new frequency bands;simplified architecture with open interfaces; and reduced/reasonableterminal power consumption. A study on the UTRA & UTRAN Long TermEvolution (UTRAN-LTE, also known as 3GPP-LTE and E-UTRA) was started inDecember 2004 with the objective to develop a framework for theevolution of the 3GPP radio-access technology towards a high-data-rate,low-latency and packet-optimized radio-access technology. The studyconsidered modifications to the radio-interface physical layer (downlinkand uplink) such as means to support flexible transmission bandwidth upto 20 MHz, introduction of new transmission schemes, and advancedmulti-antenna technologies. 3GPP-LTE is based on a radio-interfaceincorporating orthogonal frequency division multiplex (OFDM) techniques.OFDM is a digital multi-carrier modulation format that uses a largenumber of closely-spaced orthogonal sub-carriers to carry respectiveuser data channels. Each sub-carrier is modulated with a conventionalmodulation scheme, such as quadrature amplitude modulation (QAM), at a(relatively) low symbol rate when compared to the radio frequency (RF)transmission rate. In practice, OFDM signals are generated using thefast Fourier transform (FFT) algorithm.

Mobile communication devices may now have multiple communication cores,such as cellular (including 3G and 3GPP-LTE), WiFi, Bluetooth,near-field communications (NFC), high-definition radio (HDR), globalnavigation satellite systems (GNSS), and the like. Each of thesecommunication cores needs to maintain time preservation in order tooperate properly. In many current designs, each communication coregenerates its own time measurement at the required accuracy of thecommunication core.

In other mobile communication devices, a single source (such as thecellular radio) is used to provide a clock signal for all thecommunication radios in the mobile communication device. This clocksignal is unidirectional and usually requires that the clock source beon at all times, possibly affecting battery life in a negative manner,as that radio cannot enter an idle mode. It could also be set to a lowpower state, but then it affects the accuracy and availability of theclock source.

As mobile communication devices acquire more and more capabilities, thebattery life of the device becomes a more important issue. Users do notwish to have to keep their mobile communication device plugged in allthe time in order to maintain a charge on the device. One way toincrease battery life is to reduce the power consumption of the mobilecommunication device. One such way to reduce power consumption is toreduce the power used for clock generation on the device. It may also bedesirable to lower the costs of components of a mobile communicationdevice. One such method of lowering costs may be the ability to use areference clock that is not as accurate, augmented by using other timingsources. In addition, the use of multiple communication cores as timingsources could be used to increase the availability of accurate timesources, as opposed to the use of a single source for a clock signal.

An embodiment operates by dynamically selecting an accurate timepreservation source according to predefined Key Performance Indicators(KPI), including availability, accuracy, latency, noise, andreliability. Availability may just taken into account if the source iscurrently available. Accuracy may be measured in a variety of differentmanners. In one embodiment, accuracy may be defined as the maximum errorbetween the time provided relative to the absolute time. Latency may bedefined as the time it takes for the core to respond to a request. Thenoise level may include factors such as clock jitter and the like.Reliability may be an estimate of the stability of the source. It shouldbe understood that each client may have its own weighting of theindicators. Therefore, each client may add another indicator to the KPIor ignore an indicator that other clients use. Thus, it is possible fortwo different clients to choose different sources because of thedifferent indicators.

An embodiment may have two forms of time preservation: 1) coarse time,which provides an accuracy-limited interface that provides a softwarelevel interface for time reporting; and 2) fine time, which provides amore accurate interface that uses both a software level interface andhardware level signaling for the reporting of accurate time. Inaddition, a communication core may allow querying of its current timepreservation KPI values and capabilities.

As an example, a GNSS such as the global positioning system (GPS)requires a very accurate clock in order to reduce time to first fix(TTFF)—the time required to acquire satellite signals to calculateposition. If the GNSS is active and another communication core is idle,the GNSS can be used to provide an accurate time preservation interfaceto the other communication cores. But if the other communication core isactive and the GNSS is idle, the other communication core may providethe time preservation interface for the GNSS.

FIG. 1 is a block diagram illustrating a general overview of anembodiment. Mobile communication device 100 comprises communication core102, communication core 104, and communication core 106. Each of thecommunication cores may communicate via one of a variety of differentmethods, such as cellular (including, but not limited to, 3G and3GPP-LTE), WiFi, Bluetooth, near-field communications (NFC),high-definition radio (HDR), global navigation satellite systems (GNSS),and the like. For example, communication core 102 may be for LTEcommunications, communication core 104 may be for WiFi communications,and communication core may be for GNSS such as the Global PositioningSystem (GPS). Each of the communication cores is arranged to communicateto a different device using a specific protocol. For example,communication core 102 is capable of communicating with an evolved NodeB (eNB), communication core 104 is capable of communicating with a WiFiAccess Point, and communication core 106 is capable of communicatingwith a GPS satellite. It should be understood that there may also beadditional communication cores present in the system and thatcommunication cores 102, 104, and 106 may be any combination ofcommunication cores.

Arrows 110 and 112 represent a software-level interface that links twoor more of communication cores 102, 104, and 106. Arrows 120 and 122represent a hardware level signal that couple together two or more ofcommunication cores 102, 104, and 106. Each of communication cores 102,104, and 106 can communicate to another of the communication cores 102,104, and 106 for a time preservation assistance and aiding session. Eachcommunication core can decide which of the other communication coreswill be the time preservation source, so the other communication coreswill be the clients of the time preservation source. The communicationprotocol can switch with the preservation source between thecommunication cores based on specific KPI criteria. For example, aclient core may wish to switch between preservation sources when a moreaccurate preservation source become available. Or a client more maymerely be switching off of one preservation source when the sourcebecomes unavailable.

While three communication cores are illustrated in FIG. 1, it should beunderstood that a mobile communication device 100 may include adifferent number of communication cores and the concepts presented inFIG. 1 may be extended in such situations to the number of communicationcores actually present in a particular mobile communication device.

FIG. 2 illustrates another embodiment that uses a centralized component.Mobile communication device 200 comprises communication cores 202, 204,and 206. Also present is time preservation assistance and aiding manager230. Arrows 210, 212, and 214 represent a software level interface thatlinks each of communication cores 202, 204, and 206 to time preservationassistance and aiding manager 230. Arrows 220, 222, and 224 represent ahardware level signal that couples each of communication cores 202, 204,and 206 to a time manager, termed the time preservation assistance andaiding manager 230.

Time preservation assistance and aiding manager 230 contains its ownprocessing and clock resources for preserving the time. In oneembodiment, time preservation assistance and aiding manager 230 is aseparate device from communication cores 202, 204, and 206. In such asituation, time preservation assistance and aiding manager 230 preservesaccurate time based on specific KPI criteria. In another embodiment,time preservation assistance and aiding manager 230 may actually residein any of the existing communication cores 202, 204, and 206.

The time preservation assistance and aiding manager 230 is configured todecide which of the communication cores will be the time preservationsource so the remaining communication cores can be the clients of thetime preservation source. The time preservation assistance and aidingmanager 230 can switch the time preservation source between thecommunication cores 202, 204, and 206 based on specific KPI criteria. Ingeneral, time preservation assistance and aiding manager 230 shouldalways try to have the “best” time. That is, the time that is the mostaccurate, most reliable, have the least jitter, etc. It can choose itsalgorithm to ensure that it has the “best” time. In one embodiment, timepreservation assistance and aiding manager 230 may periodically querycommunication cores 202, 204, and 206 and decide whether to ask for timeassistance to improve its own time.

If communication core 202 is the time preservation source andcommunication cores 204 and 206 are clients, both communication core 204and communication core 206 can turn off or otherwise reduce the powerconsumption of a clock contained within the communication core, becausecommunication core 204 and communication core 206 will be receiving timeinformation from the time preservation source. Time preservationassistance and aiding manager 230 contains interfaces at both thehardware and software levels that can be used to provide timepreservation services to the various communication cores.

Time preservation assistance and aiding manager 230 may also beconfigured to determine a time preservation source for time preservationassistance and aiding. This method can be based on any predefined TimePreservation KPIs criteria (e.g., accurate clock, availability,validity). This will be presented in further detail below.

While three communication cores are illustrated in FIG. 2, it should beunderstood that a mobile communication device 200 may include adifferent number of communication cores and the concepts presented inFIG. 2 may be extended in such situations to the number of communicationcores actually present in a particular mobile communication device.

With reference to FIG. 3, a flowchart illustrating the operation of anembodiment is shown.

In this example, one of the communication cores, e.g., core 1(communication core 102 from FIG. 1), requires time preservation aiding.Core 1 queries one of the other communication cores, e.g., core 2,determining the KPI of the core and requesting time preservation aidingservices, if the KPI meets the criteria for core 1 (302). If core 2 isnot able to provide such services (304), core 1 queries the nextcommunication core (306). There may be several reasons why a particularcommunication core is not able to provide time preservation aidingservices. For example, a particular communication core may be in an idlemode for power saving reasons, or the communication core may be busyperforming other tasks, resulting in a drop of the latency, which wouldaffect the KPI of the core. Or the core may not be meeting clientexpectations, resulting in a change in the KPI.

When core 1 finds a core that is able to provide the time preservationaiding services, core 1 requests for time preservation aiding. As aresponse core 3 response with accurate time preservation stamp (308) andhardware (HW) signaling when this time preservation arrives (310). Core3 continues by sending a time preservation status report (312). The timepreservation stamp may serve as the coarse time described above—asoftware level interface for time reporting. While the HW signalingprovides the fine time interface. There may be situations where aparticular communication core only wants coarse time. The HW signalingmay be omitted in such a case.

As a result core 1 now has time preservation information. In fact, core1 can now provide time preservation assistance if another core, e.g.,core 2, requests assistance.

At any time, core 1 may need to switch to using another core, e.g., core2 as the source for timing information. There may be a variety ofreasons for this to happen. For example, core 3 may be switched to anidle state and be unable to perform signaling duties. Or core 3 may havebeen be receiving timing signals from an external source, but has lostconnection to the external source. Or the performance of core 3 hasotherwise deteriorated such that it does not meet the KPI criteria ofthe client. In a situation where core 1 needs to switch to another core,the flowchart of FIG. 3 can be followed to establish connection to adifferent timing source.

Any of the communication cores could be used as the timing source. Theremay be an instance where core 1 and core 3 switch places and core 1becomes the timing source and core 3 becomes the client.

With reference to FIG. 4, a flowchart illustrating the operation ofanother embodiment using a centralized time preservation assistance andaiding manager is shown.

In this example, the time preservation assistance and aiding managerbegins with acquiring initial time information from an external source(402). This external source may be any type of source of time, forexample, a remote Network Time Protocol (NTP) server or another sourcefor accurate time. The time preservation assistance and aiding managermay be configured to constantly search for an accurate time preservationsource, to keep itself available for providing service of accurate timepreservation assist.

With the time preservation assistance and aiding manager having anaccurate clock, the communication cores do not need to request for timeassistance from other communication cores. A communication core can makea request to the time preservation assistance and aiding manager (404).Thereafter, the time preservation assistance and aiding manager canprovide a time stamp to the requesting communication core (406). Thetime preservation assistance and aiding manager can provide also providehardware signaling with time information to the communication core(408). The time preservation assistance and aiding manager can also senda time preservation status report as needed (410).

There may be instances where a communication core only desires to findout the current time (406). This may occur if, for example, thecommunication core periodically checks if its own clock is accurate.Because of the presence of the time preservation assistance and aidingmanager, a clock internal to a communication core need not be asaccurate as was needed in the prior art, because the communication corecan periodically request a time stamp from the time preservationassistance and aiding manager. In such a situation, establishinghardware signaling between the time preservation assistance and aidingmanager and the communication core may not be necessary.

There may be instances when an external timing source is not availableto the time preservation assistance and aiding manager. In such asituation, the time preservation assistance and aiding manager can usethe procedure set forth with respect to FIG. 3, requesting timepreservation aiding services from one of the communication cores.Thereafter, once the time preservation assistance and aiding manager hasreceived timing information from one of the communication cores, it canact as the timing source for other communication cores.

With reference to FIG. 5, a block diagram of a system using anembodiment is shown. Communication core 502, communication core 504, andcommunication core 506 may be as described above, with variousconnections between the communication cores, such as connection 510 andconnection 512. It should be understood that there may be otherconnections between the cores that are not illustrated. Communicationcores 502, 504, and 506 make up a device 530. Device 530 may or may notbe contained within a single package. Device 530 is coupled to anantenna assembly 540. Communication cores 502, 504, and 506 would beconfigured to transmit and receive data using antenna assembly 540.Device 530 is also coupled to memory 550. Memory 550 may use any form ofmemory, such as RAM, flash memory, ROM, and the like. Memory 550 couldbe used to store programs to be executed on communication cores 502,504, and 506, or other aspects of device 530 that are not shown. Memory550 could also be used to store user data, such as a contact list,music, and the like. It should be understood that device 530 may containmany other components that are not illustrated in FIG. 5. Exemplarycomponents may include user interfaces such as displays and keypads,speakers, and microphones, and any other component that may be used in amobile communication device.

It should be understood that, although portions of this document discusscommunication cores, it is not so limited. The concepts presented heremay be applied to electronics with a plurality of any type of core, suchas a computing core, or mixed cores, such as both computing cores andcommunication cores.

The following examples pertain to further embodiments.

A system may comprise a first communication core and a secondcommunication core. The first communication core may be arranged toprovide timing information to the second communication core and thesecond communication core is arranged to provide timing information tothe first communication core.

In another embodiment, the first communication core is arranged toprovide timing information via both software and hardware to the secondcommunication core. The second communication core is arranged to providetiming information via both software and hardware to the firstcommunication core.

In another embodiment, a time manager is coupled to both the firstcommunication core and to the second communication core. The timemanager may be arranged to provide timing information to the firstcommunication core and the second communication core. The time managermay be further arranged to receive time information from a sourceexternal to the system.

In another embodiment, the time manager is further arranged to receivetiming information from the first communication core and the secondcommunication core.

In another embodiment, the system also comprises a third communicationcore, wherein the third communication core is arranged to select betweensaid first communication core and said second communication core toprovide timing information, based on Key Performance Indicators.Furthermore, the first communication core is arranged to select betweensaid second communication core and said third communication core toprovide timing information, based on Key Performance Indicators. Inaddition, the second communication core is arranged to select betweensaid first communication core and said third communication core toprovide timing information, based on Key Performance Indicators.

In another embodiment, the Key Performance Indicators includeavailability as a timing source, accuracy as a timing source, andreliability as a timing source.

A method for maintaining timing in a multiple-communication core systemmay comprise requesting time preservation services from a firstcommunication core to a second communication core in the system and ifthe second communication core is able to provide time preservationservices, transmitting a time-stamp from the second communication coreto the first communication core.

In another embodiment, the method may further comprise establishing ahardware coupling for timing signals between said first communicationcore and said second communication core; and providing timing signalingover the hardware coupling.

In another embodiment, the method may further comprise: sending a timepreservation status report from the second communication core to thefirst communication core.

In another embodiment, the method may further comprise terminating thehardware coupling if it is determined that the second communication corecan no longer provide time preservation services.

A method for maintaining timing in a multiple-communication core systemmay comprise: initializing a timing manager within the system withtiming information; requesting time preservation services from acommunication core to the timing manager; and providing a time stampfrom the timing manager to the communication core.

In another embodiment, the method may further comprise creating a timepreservation status report.

In another embodiment, initializing the timing manager may comprisereceiving timing information from an external source. The externalsource may be a network time protocol (NTP) server.

In another embodiment, the method may further comprise establishing ahardware coupling to provide a time signal from the timing manager tothe communication core.

In another embodiment, initializing the timing manager may comprisereceiving timing information from a communication core internal to thesystem.

While certain features of the invention have been illustrated anddescribed herein, many modifications, substitutions, changes, andequivalents may occur to those skilled in the art. It is, therefore, tobe understood that the appended claims are intended to cover all suchmodifications and changes as fall within the true spirit of theinvention. It should be understood that, although embodiments weredescribed in the context of a mobile communication device, the methodsand systems described herein may be applicable to any piece ofelectronic equipment.

We claim:
 1. A mobile device comprising: a first communication core; asecond communication core; wherein, said first communication core isarranged to provide timing information to the second communication core;and said second communication core is arranged to exchange timinginformation with the first communication core.
 2. The mobile device ofclaim 1 wherein: said first communication core is arranged to providetiming information via both software and hardware to the secondcommunication core; and said second communication core is arranged toprovide timing information via both software and hardware to the firstcommunication core.
 3. The mobile device of claim 1 further comprising:a time manager coupled to both said first communication core and to saidsecond communication core; wherein, the time manager is arranged toprovide timing information to the first communication core and thesecond communication core.
 4. The mobile device of claim 3 wherein thetime manager is further arranged to receive time information from asource external to the system.
 5. The mobile device of claim 3 whereinthe time manager is further arranged to receive timing information fromthe first communication core and the second communication core.
 6. Themobile device of claim 1 further comprising a third communication core,wherein said third communication core is arranged to select between saidfirst communication core and said second communication core to providetiming information, based on Key Performance Indicators; said firstcommunication core is arranged to select between said secondcommunication core and said third communication core to provide timinginformation, based on Key Performance Indicators; and said secondcommunication core is arranged to select between said firstcommunication core and said third communication core to provide timinginformation, based on Key Performance Indicators.
 7. The mobile deviceof claim 6 wherein said Key Performance Indicators include availabilityas a timing source, accuracy as a timing source, and reliability as atiming source.
 8. The mobile device of claim 1 wherein the mobile deviceis user equipment (UE) and the first communication core is arranged tocommunicate with a Long Term Evolution (LTE) network.
 9. The mobiledevice of claim 8 wherein the second communication core is arranged tocommunicate with a WiFi network.
 10. A method for maintaining timing ina multiple-communication core wireless communication device, the methodcomprising: requesting time preservation services from a firstcommunication core to a second communication core in the wirelesscommunication device; and when the second communication core is able toprovide time preservation services, transmitting a time-stamp from thesecond communication core to the first communication core.
 11. Themethod of claim 10 further comprising: establishing a hardware couplingfor timing signals between said first communication core and said secondcommunication core; and providing timing signaling over the hardwarecoupling.
 12. The method of claim 11 further comprising: sending a timepreservation status report from the second communication core to thefirst communication core.
 13. The method of claim 10 further comprising:terminating the hardware coupling if it is determined that the secondcommunication core can no longer provide time preservation services. 14.The method of claim 10 wherein: the first communication core is arrangedto communicate with a Long Term Evolution (LTE) network.
 15. The methodof claim 14 wherein: the second communication core is arranged tocommunicate with a WiFi network.
 16. A method for maintaining timing ina multiple-communication core wireless device comprising: initializing atiming manager within the system with timing information; requestingtime preservation services from a communication core to the timingmanager; and providing a time stamp from the timing manager to thecommunication core.
 17. The method of claim 16 further comprisingcreating a time preservation status report.
 18. The method of claim 16wherein initializing the timing manager comprises receiving timinginformation from an external source.
 19. The method of claim 18 whereinthe external source is a network time protocol (NTP) server.
 20. Themethod of claim 16 further comprising: establishing a hardware couplingto provide a time signal from the timing manager to the communicationcore.
 21. The method of claim 16 wherein initializing the timing managercomprises receiving timing information from a communication coreinternal to the wireless device.